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SUNPAP - FINAL SUMMARY REPORT

Nano fibrillated cellulose (NFC) is one of the most promising nanomaterials for wide-variety

applications. However, when the project was started, NFC was prepared and applied in

papermaking mainly on a lab scale. The target of the SUNPAP project was first to up-scale the NFC

production processes, and then to adapt this nanomaterial for modern papermaking processes via the

demonstrated pilot lines.

The energy consumption of NFC production is high and needs to be reduced. The high potential

could be seen with a combination of the mechanical refining and enzymatic pre-treatment before

homogenization or with pre-treating the pulp fibres by oxidative chemicals without intensive

refining. Based on these findings, a new pilot line with high pressure homogenizers was built at

CTP in parallel to this project, and the semi-pilot scale rotor-/stator-machine at PTS was completely

re-engineered in order to produce NFCs for other project partners. Three different NFCs (from

aggregates of microfibrils to fine individual nanofibrils) were produced on a large scale and these

were used for the production of the selected demonstrators. The main conclusion of the material

cost calculations was that the chemical costs of the chemically pre-treated NFCs out-weighed the

higher electricity and capital costs of the enzymatically pre-treated NFC.

NFC does not only offer possibilities to improve the current products on the market, but makes it

possible to develop completely new types of value added products for niche markets. In

conventional pigment coating trials, no major benefits were gained via NFC in pigment coating

colour. Increased drying demand due to the low solids will limit the used amounts. However, there

are some possibilities to use NFC as a rheology modifier or to improve some critical product

properties. For example, in the case of coated inkjet photo paper, the production speed is normally

limited by cracking during drying. The use of small amounts of NFC in the curtain coating had a

clear positive impact on both inkjet paper quality and production efficiency (higher speeds can be

used). NFC can also give a good grease barrier in multilayer barrier products and can replace partly

non-renewable materials. In a similar way, the drying quality of the dispersion (polyvinyl alcohol)

coating layer was improved with the use of NFC. As the second-layer barrier, latex or extrusion

coating with PE further improved the barrier properties when coated on top of the polyvinyl alcohol

and NFC layer. Novel products with active properties are possible with functionalised NFCs. Very

high antibacterial activity of papers could be achieved with thin layers of NFC-TiO2 and/or ZnO,

and NFC-TiO2 also has significant activity for the oxidation of NO and NOx with low coat weights.

Thin layers can be applied with the novel foam applicator installed by VTT on a pilot scale. NFC

containing aggregates gave, in most cases, results as good as those from fine NFC.

Sustainability assessment showed that the changes in environmental impacts for the pigment

coating case were negligible, due to very small amounts used. However, for the bulk structures, the

trend was very positive, radically lower environmental impacts were achieved when the use of NFC

also enabled lower basis weight, due to the higher strength. The presence of NFC in demonstrators

did not induce large changes in recycling/de-inking. The tested coated board products, including

NFC in the coating layer, passed the different biodegradability tests and their compostability was

confirmed. NFCs are viscous gel-type materials and are used mainly in wet form. The toxicological

studies in vitro and in vivo did not indicate any major concerns, except for occupational inhalatory

exposure, which, however, can be managed by standard protective measures. NFCs seem to be

biodegradable and non-toxic, and no big changes in safety or recycling of products containing NFC

are expected in the future.

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1. A summary of the description of the project context and objectives

The SUNPAP project (Scaling-Up Nanoparticles in modern PAPermaking) addressed the

competitiveness of the European paper industry by means of nanocellulose-based processes to

provide radical product performance improvements, new efficient manufacturing methods, and the

introduction of new added-value functionalities. Nano fibrillated cellulose (NFC) is the most

promising nano-material for wide-variety applications in papermaking. However, when the project

was started, NFC was mainly prepared and applied on a lab scale. The target of the SUNPAP

project was first to scale up the NFC production processes, and then to adapt this nanomaterial for

modern papermaking processes via the demonstrated pilot lines. The scientific work was divided

into four research modules (Figure 1). They have strong synergy and were well integrated with each

other.

Figure 1. Project structure.

The main practical targets of the SUNPAP project can be summarised as follows:

1. Development and up-scaling of novel processes for the energy efficient production of

nanomaterials, namely NFC, on a pilot scale (in Module NFC Production).

2. Development and up-scaling of NFC modification processes to address the challenges of

papermaking and to provide added-value active functionalities (in Module NFC Processing).

Building and demonstration of pilot lines to alleviate take-up of nanotechnologies,

both for the production and the utilisation of NFC, to the modern papermaking

processes (in Modules NFC Production and Processing).

3. Exploitation of innovative sustainable solutions for the whole paper industry value chain by

integrated sustainability assessment approaches based on economic, social, and

environmental impact assessments (in Module Value Chain).

4. Risk assessments to guarantee the safe introduction of nanotechnologies in the whole value

chain of conventional industrial paper production processes and final paper based products

(in Module Health and Safety).

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The final goal of the SUNPAP project was to enable the introduction of NFC based processes in

various types of applications in the papermaking value chain (Figure 2) and the main aims were to

develop and demonstrate:

1. High-performance products and environmentally friendly NFC-enabled production

processes, demonstrated for graphical papers and packaging boards

2. Functional products and innovative processes enabled by NFC with active functionalities,

demonstrated for papers and packaging materials

3. High-added-value fibre-based products with highly specific properties made possible by

NFC, demonstrated for fibre-based filters and other selected innovative materials.

Figure 2. The targeted applications of the project in the papermaking value chain.

The first main target was studied in NFC Production (Module 2) and the research work was focused

on the material development: NFC production and modification processes, and optimising the

processes for the up-scaling of NFC production (including a part of the main third target, to build

and demonstrate pilot lines). The activities were directed towards the three main technical

challenges of the project, energy efficient NFC production (WP 4), high quantities of NFC, and

control of NFC suspension rheology (WP 5). The purpose of Module 2 was to produce various

types of native and modified NFC batches, which were used in Module 3 for the product

demonstrations. The main objectives of Module NFC Production were:

1. Preparation of NFC from cost-competitive pulp raw materials

2. Development of process concepts for cost-efficient preparation of NFC on a pilot scale

3. Preparation of user-friendly NFC for different kinds of papermaking processes

4. Production of NFC with active properties on a pilot scale for added-value paper products

The second main target was studied in NFC Processing (Module 3), which developed the NFC-

enabled process (including a part of the main third target to build and demonstrate pilot lines) and

product concepts (WP6) and finally produced demonstrations of the developed concepts (WP8).

The proper industry steering was realised by active participation of the industry partners already in

the main research tasks. The focus of WP7 was to provide theoretical tools for the optimisation of

the rheology of the NFC suspensions. The overall objectives of Module NFC Processing were the

following:

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1. Control of reactions and conditions of NFC in wet-end and coating processes

2. Development and design of NFC-enabled product concepts to use the full potential of NFC,

in terms of its dimension, optical, strength, specific surface area, and functional properties

3. Prediction of optimal NFC-based process operation parameters by simulation of rheology of

suspensions and coatings that include NFC as a main component

4. Demonstrations of the concepts for three selected end-use areas

The fourth main target was studied in the Value Chain (Module 1), which was focused on the

generation of a holistic view of the value network of the NFC-based processes and products,

ranging from the raw materials to the end of life of the products, in order to design the demonstrated

product concepts for the market areas with the best potential. This module contained three WPs,

which were all essential when evaluating the possible success of the NFC product value chain,

starting from raw materials and production, and ending up at recycling and end-of-life assessment.

Here, the first work package, WP 1, concentrated on evaluating the financial grounds and means for

producing NFC by combining market analysis with production prospects. WP2 determined the

sustainability of potential NFC value chains and analysed effects of new products on social,

economic, and environmental areas. WP3 focused on recyclability and biodegradability issues

regarding NFC. This included analysis of both eco-toxicological impacts and biodegradation of new

functional materials. An important role of the work packages was the communication with other

partners and the delivery of the results to WP10, Risk Assessment. The aims of the module Value

Chain were:

1. Assessment of economic grounds for production of NFC-based products and a

determination of the most beneficial applications and market areas

2. Evaluation of the economy of the value chain. Assessment of profitability for chosen

products and determine the most promising value chains for production, taking into account

current and emerging market needs.

3. Guidance and support for the focus of the project in a sustainable direction, by evaluating

sustainability aspects (environmental, social, and economic) of the developed processes and

value-added paper products throughout the whole value chain, from raw materials to end-of-

life analysis

The fifth main target was studied in Health & Safety (Module 4), which evaluated the toxicity of the

nanomaterial used in the project and performed risk assessments in order to provide information

about possible obstacles to market access and industrial take-up of the project results. This module

contained two WPs. WP9 was devoted to actual testing of nanocellulose and functional

nanocellulose (NFC and FNFC), and WP10 to the risk assessment based on the available

information and the results supplied by WP1 Market Needs, WP2 Sustainability Assessments, WP3

Recyclability and Biodegradability, WP9 Toxicity, and other parts of the project. The aims of the

module Health & Safety were the following:

1. Generation of exposure models for in vitro and in vivo studies

2. Research of the bioactivities of the NFC and functionalised NFC at cellular level

3. Research of systemic toxicity of the NFC and functionalised NFC in in vivo trials

4. Creation of an overall understanding of the environmental, health, and safety risks related to

the raw materials and products developed in this project

5. Guidance for other parts of the project, to develop low-risk products by serving as an

information source.

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2. A description of the main S&T results/foregrounds

The scientific and technical results are described, starting from material development. Material and

process studies were made in order to deliver different NFC qualities for application development.

Application studies were first carried out on a laboratory scale, and continued as product and

process studies on a larger scale for final demonstrations. Commercial microcellulose or micro

fibrillated cellulose (MFC, Arbocel®), which is a coarser material than NFC, was used in some

cases as a reference material or when the suitability of test procedures was assessed. The

sustainability assessment of the value chains and the risk assessment of the novel processes and

products were studied throughout the project, but are here described last.

NFC production (Module 2) - process and material development

WP4 NFC fabrication: The main objective of WP4 was to develop concepts for energy-efficient

preparation of NFC on a pilot scale and to identify optimal pulp raw materials for NFC preparation.

Both targets were the keys to producing cost-efficient NFC. An essential part of WP4 was to deliver

NFC samples to other partners for other research tasks.

These objectives were considered by taking into account different chemical and enzymatic pre-

treatment methods and the influence of pulp composition on NFC fabrication. The results were

transferred to different kinds of homogenization techniques, both in industrially available facilities

for the production of micro fibrillated celluloses and pilot-scale rotor-stator-machines, and high

pressure homogenizers were used in the experiments.

It was seen that two different routes of the pulp pre-treatments have the highest potential to reduce

the energy consumption of NFC production:

Combining mechanical refining and enzymatic pre-treatment before homogenisation, which,

after homogenisation, led to gel-type NFC, containing mainly aggregates of microfibrils.

Pre-treatment of pulp fibres by means of oxidative chemicals (TEMPO) without intensive

mechanical refining before pre-treatment, which after homogenisation led to transparent gels

with individual nanofibrils.

Especially in the preparation of NFC based on enzymatic pre-treatment, the energy consumption in

the refining stages varied depending on the used pulp raw material. It was concluded that all

commercial pulps can be used, but dissolving pulps (sulphite pulps) were best because of their low

refining resistance in the refining stages and their sensitive reaction towards the enzymes (Figure 3).

However, no mechanical refining before the final homogenisation was necessary in the production

of NFC with oxidative pre-treatment of the pulps (TEMPO). Even fewer passes at high pressure

could be realised, because after two passes, the pulps were completely homogenized. The

optimisation of the TEMPO oxidation conditions for pilot-scale studies was performed using a

design of experiment methodology by means of a composite central design (CCD) on a small scale.

The optimisation was based on minimising time and chemical additions in order to maximise the

yield, fines content, and number of carboxyl groups. This NFC, produced with low energy

consumption using TEMPO oxidation, showed a remarkably lower viscosity than the reference

materials, which were actually the target in WP5.

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Figure 3. Influence of enzyme pre-treatment on energy consumption during refining of

different pulps (pulp A = softwood dissolving pulp, pulp B = softwood kraft pulp,

pulp C = birch kraft pulp, pulp D = eucalyptus dissolving pulp). Control = without

pre-treatment, EGL = with enzyme pre-treatment.

Based on these findings, the most suitable high-pressure homogenizers and a rotor-/stator-machine

were selected to produce NFC on a pilot scale for other project partners. The high-pressure

homogenizers were bought and the pilot line was built at CTP in parallel with this project. The

geometries of the tools from the rotor-/stator-machine were completely re-engineered to produce

NFC products using a technique not used before at PTS. In total, more than 100 kg of NFC was

produced for other partners. The results of the produced NFC qualities on a large scale are shown in

Figures 4 and 5:

1. NFC-CTP = enzymatically pre-treated pulpcombined with mechanical refining followed by

high pressure homogenizer

2. NFC-TE/CTP = TEMPO-oxidised pre-treated pulp followed by high pressure homogenizer

3. NFC-TE/PTS = TEMPO-oxidised pre-treated pulp followed by rotor-/stator-machine

Figure 4. Light microscopy pictures of NFC-CTP, NFC-TE/CTP, and NFC-TE/PTS.

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Figure 5. TEM pictures of NFC-CTP, NFC-TE/CTP, and NFC-TE/PTS.

TEM pictures showed that an enzymatically pre-treated and homogenised sample (NFC-CTP) was mainly

aggregated microfibrils with only partly a nanostructure; NFC with TEMPO oxidation and a homogenised

sample (NFC-TE/CTP) contained mainly nanofibrils; and NFC with TEMPO oxidation and rotor-stator

treatment (NFC-TE/PTS) cut the fibres resulting in short but thick macrofibrils. As it can be seen, it was

possible to produce different kinds of NFC structures, but it was still hard and time consuming to analyse the

NFC properties. For this reason, fractionation tools were developed to reveal more about what is inside NFC

samples, and NFC quality assurance tools were investigated to establish protocols for reliable quality testing

in the production of NFC. In order to characterise the different NFC qualities, a complex fractionation

system at VTT was established, where the sizes of different fractions could be measured and analysed. As it

can be seen in Figure 6, most parts of all produced NFC qualities were in the range of > 0.1 µm. The

fractions > 1 µm probably contain mainly aggregates and therefore they do not go through the wide slots.

The fraction < 0.1 µm contained mainly dissolved solids.

Figure 6. Share of different fractions in different NFC qualities produced for pilot trials (NFC-

CTP, NFC-TE/CTP, NFC-TE/PTS).

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WP5 NFC Functionalisation: The main objective was the development of NFC modification

processes to impart innovative functionalities to NFC. The functionalisation of NFC was carried out

with the following targets: - Development of hydrophobic NFC suspensions with a controlled viscosity profile suitable for

the applications in paper production processes

- Development of NFC with active properties for special paper applications

NFC surface energy modification to impart hydrophobic properties: Different approaches were

applied, such as physical adsorption of polymers on the NFC surface, as well as chemical

modifications of NFC. Chemical grafting of hydrophobic moieties was studied in organic as well as

aqueous media, such as nano-emulsion approaches.

Physical adsorption of polymers on the NFC surface: Industrial copolymers, polyvinyl alcohols

(PVA), were used for the NFC modifications. Physical adsorption of polyvinyl alcohol on NFC

resulted to be a relatively simple method of modifying the NFC viscosity. The addition of polyvinyl

alcohol significantly decreased the NFC suspension shear viscosity and the modification did not

depend on the different polyvinyl alcohol grades (Figure 7). The effects on suspension viscosity

were rather slow and the studies were carried out on a laboratory scale. By adding polyvinyl

alcohol, a significant increase in NFC suspension concentration, about 3 times, could be reached

without viscosity increasing.

Figure 7. Physical adsorption of PVA on NFC surface decreased viscosity.

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Chemical grafting by nano-emulsion approach: An interesting route for NFC chemical grafting

was the nano-emulsion approach, where nano-emulsions (20-200 nm micelles) containing AKD

(alkylketendimer to be grafted onto NFC to impart hydrophobic properties) were produced and

mixed with NFC suspension. After removal of the CHCl3 solvent, the NFC-AKD suspension was

ready for chemical grafting (activation) obtained after the drying process. The activation (drying)

step can be alternatively performed before application to paper, to obtain a dry NFC-AKD re-

dispersible additive or, in the case of after bulk application, in the paper production process when

the paper web is dried (Figure 8).

Figure 8. Chemical crafting by nano-emulsion decreased viscosity of NFC suspension.

Based on the laboratory work, NFC-AKD suspension displays a significant reduction of viscosity in

coating colour formulations with respect to non-modified NFC (NFC-CTP, Figure 9):

Figure 9. Chemical crafting by nano-emulsion decreased viscosity of coating colour by 84%

compared to natural NFC.

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Active NFC functionalisation by inorganic nanoparticle addition: Innovative inorganic

nanoparticles/NFC hybrid systems (nano-composites) were developed, and the selected NFC

functionalisation was obtained by the addition of inorganic nanoparticles. Two main routes were

followed: polyelectrolyte assembly and direct physical adsorption. NFC-Ag and NFC-ZnO Nano

composites were obtained by electrostatic assembly of inorganic nanoparticles (Ag and ZnO) on the

NFC surface. Different polyelectrolytes were investigated as macromolecular linkers between

inorganic fillers and NFC. These nano-composites were applied on paper by coating. The SEM

images of NFC/Ag nano-composites obtained using different numbers of deposition cycles – (a)

Ag/PDDA1 (n=1); (b) Ag/PDDA5 (n=5) and (c) NFC-ZnO nano-composite – are shown in Figure

10.

Figure 10. SEM images of NFC/Ag nano-composites obtained using different numbers of

deposition cycles: (a) Ag/PDDA1 (n=1); (b) Ag/PDDA5 (n=5); (c) NFC-ZnO nano-

composite.

The obtained nano–composites, as well as coated paper, showed significant antibacterial activity

(Table 1 and Figure 11).

Table 1. Antibacterial effect of paper coated with NFC/Ag starch-based coating.

Paper sample Inicial inoculum

(log CFU T0)

After contact

(log CFU T18h)

Bacteriostatic

activity

(log reduction)

Bactericidal activity

(log reduction)

Untreated paper 5.3 7.5 - -

Starch 7.1 0.4 -

NFC-Ag/starch 4 3.5 2.2 1.8

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Figure 11. Antibacterial activity of coated papers by NFC-ZnO nano composites.

NFC-ZnO and NFC-TiO2 nano-composites were prepared by physical adsorption, by mixing NFC

and inorganic nanoparticle suspensions. The nano-composites showed strong antibacterial activity,

with respect to gram positive bacteria: Staphylococcus aureus and Bacillus cereus spores, as well as

gram negative Klebsiella pneumonia (Table 2).

Table 2. Antibacterial activity, with respect to gram positive bacteria: Staphylococcus aureus

and Bacillus cereus spores, as well as gram negative Klebsiella pneumonia.

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NFC processing (Module 3) – applications, modelling, and demonstrations

WP6 NFC Application: The main objective of WP6 was to develop and design NFC-enabled

product concepts to utilise the full potential of NFC in both coating and wet-end processes.

Furthermore, we aimed to master the composition of coating colours for both conventional and

advanced coating processes in pilot surface treatment studies. The target of the wet-end lab studies

was to control reactions and conditions of NFC wet-end processes application and to optimise and

scale up the NFC application processes from hand sheets to pilot scale for the application of native

and functionalised NFCs to value chains.

Several lab studies using NFC as a replacement for latex or other co-binders in different types of

surface treatments were carried out with various natural NFC and modified or functionalised NFC

samples. Surface strength and mottling are critical factors in the conventional pigment coatings.

The main findings from NFC in conventional pigment coating were increased viscosity of the

coating colours, porosity of the filter cake and porosities of the coating layers when NFC was added

to the coating colours, and decreased gloss of the coated products. Removal of viscosity modifiers

widened the operational window (low shear rate viscosity). The surface strength results obtained

were inconsistent and partly poor, most probably due to the low speed used on the lab scale.

NFC can also be used to improve the barrier properties of the packaging materials. The conclusions

of the introduced NFC in a plasticised starch matrix are strong improvement of barrier properties

(WVTR), and a positive effect was expected for OTR with no degradation of mechanical

properties. The cooking of starch matrix directly in NFC suspensions at 95°C did not have any

significant impact on NFC properties, and therefore it is a good choice for preparing NFC-based

coating colours. Secondly, the study of modified NFC showed that modifications are interesting

techniques to reduce the viscosity of NFC suspensions by decreasing interactions between fibrils.

The coating colours produced with modified NFC also had much lower viscosities than colours

made with unmodified NFC. This was an important result because this improved a lot of the

processability of NFC-based barrier coating colours, while keeping the same barrier properties.

However, the use of NFCs had still a big drawback: their high viscosity at low solids led to

formulations with very low solid content. In practice, only small amounts of NFC could be

introduced.

Thin layers of cellulose nanofibrils (0.5-2 g/m2) could be applied on the surface by using a novel

foam coating applicator. The use of air instead of water makes the application of viscous cellulose

nanofibril solutions possible (Figure 12). The main focus in the beginning was on the

characterisation of foam and foam-coating trial procedures in order to scale up the use of NFC in

the foam-coating process. The stability of the foam is an important foam property, besides the

bubble size and bubble size distribution. The best indicator for the stability was the back pressure

value measured by the foam generator.

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Figure 12. a) NFC in feeding tank (left), b) foamed NFC before application unit (middle), and

c) VTT´s narrow slot-type applicator in a large-scale pilot coating machine (right).

The main part of the work concentrated on solving technical questions in scaling up the foam

coating application. Using infrared driers instantly after the applicator, and the new backing roll for

the pilot coating line, improved coating quality. The mixing head with fewer pins made a higher

solid content of NFC possible (1% -> 3%), which in practice made higher coat weights possible at

the same time. Differences in contact angle, air permeability, roughness, and microbiological

influence between different natural and modified/functionalised NFCs were noticed. The foam-

coating process is a suitable method for the application of NFC on the fibre based substrates. The

highest speed with the current pilot configuration was 300 m/min, and with higher speeds, an extra

air removal device is needed (to remove air from the web). The solid content of NFC is critical and,

with studied qualities, is low, but it is much higher than can be used in spray coating. NFC quality

is very important; big particles/aggregates can block the applicator. VTT now has this technology

available for paper and board coating studies on a pilot scale. It can also be used for the application

of any novel materials giving special functionalities to products with small addition levels.

Lab studies to use NFC as an additive in order to improve strength in the wet-end were carried out.

The retention evaluation showed that it seemed to be necessary to use retention aids to retain the

NFC. Retention of NFC in the paper sheet depends strongly on the pulp and retention aid used, as

well as on the basis weight. NFC leads to a significantly increased dewatering resistance of

hardwood chemical pulp. This negative impact could be reduced by using cationic additives.

Especially for softwood chemical pulp and CTMP, the loss in dewatering speed was lower

compared to hardwood. Retention aids and special starch products can enhance the dewatering

speed when using NFC, and NFC is generally capable of improving the paper strength very

significantly. Especially for the paper board, some opportunities based on the small-scale pilot

results exist for using the increase in strength to save fibre raw materials. NFC in the outer layers

can significantly contribute to the stiffness of paper board. At lower dosages, the loss in bulk could

be compensated by an increase in E-modulus (SW and CTMP, as well). There are also

opportunities to produce CTMP to a lower SR with higher bulk. The reduced delaminating could be

compensated by NFC, while the bending stiffness can be improved.

WP7 Multi-scale modelling had two main objectives: prediction of nonlinear dynamic material

interactions in suspensions for varied process conditions, with atomistic models and simulation of

rheology of suspensions and coatings, including NFC as a main component with continuum level

models. Atomistic models were used as qualitative input to the continuum level models. The studies

increased scientific understanding of the related phenomena in the characterisation of NFC such as

thixotropy and viscoelasticity.

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The molecular dynamics simulations were carried out to obtain information on the mutual

interaction between cellulose fibrils and on the interaction between cellulose fibrils and a calcium

carbonate surface. The context was to obtain parameters for the aggregation model. The main

finding from the atom-scale molecular dynamics simulations was that pushing crystalline cellulose

fibrils towards a calcium carbonate surface led to repulsion, due to a water layer stuck in between

two hydrophilic surfaces. On the other hand, there was strong binding between cellulose and

calcium carbonate in simulations with an initial structure chosen so that a cellulose fibril was

attached to a calcium carbonate surface without a water layer in between. Pulling the cellulose fibril

apart from this initial configuration led to disintegration of the fibril instead of simple desorption.

For cellulose-cellulose interaction, the situation was similar. The amorphous coverage of the fibrils

was found to be important in the binding of the fibrils together.

In the aggregation model, the mixing of NFC and calcium carbonate particles with varying particle

sizes for both species has been studied. The model was prepared in the spirit of the Smoluchowski

mass balance equations, extending it to allow for interactions between different species of

aggregates. The model was applied to study a calcium carbonate - NFC mixture suspension. The

main finding was that the NFC aspect ratio had a crucial role in the mixing of the two phases,

having a large impact on the amount of excess calcium carbonate. Obviously, the mass ratio

between the different species also affected the mixing efficiency and dynamics.

The interactions of the carboxylated fibril with non-modified nanocellulose structures were found

to have two distinguishable forms: a strong electrostatic repulsion due to a large negative surface

charge, and weak attractive interaction due to forming dynamic hydrogen bonds. The hydrogen

bond formation mostly involves the fibrils’ corners, probably due to the electrostatics geometry

and/or water structuring and screening effects, and is not related to the presence of unmodified

groups in some corner chains. Instead, the interactions between two unmodified fibrils led to

stronger hydrogen bonds and aggregation. Two carboxylated fibrils, on the other hand, are

immediately and powerfully repelled from each other. Hence, the carboxylation prevents fibrils

from aggregating into larger forms, as has been clarified at the molecular level.

The main findings described the influence of shear transients and shear localisation on the

rheometer reported as viscosity commonly used to characterise suspensions to help the design of

the pilot-scale application of new materials. It was found that the characterisation of the NFC on the

basis of viscosity can give results that are misleading if not carefully analysed. With this material,

there is no such thing as a standard rheological characterisation. Viscosity, generally used as a

characteristic parameter with implications for the processability of suspensions, is not unique for

such a complex material. This is due to the fact that the Newtonian assumption of stress and shear

rate relation contains extra components that are not purely viscous. The model was fitted at

qualitative level to experimental rheological data. The fitting was then used to simulate the

occurrence of shear banding in rotating cylinder geometry. The reported NFC suspension

experiments were performed in parallel rotating plate geometry. However, similar phenomena can,

within reason, be expected to appear in that case since, as it is well known, the shear and stress

distributions are even more heterogeneous for that particular geometry. Furthermore, it was shown,

using simple analytic calculation, that the perfect power-law scaling observed in the TEMPO-

oxidised NFC flow curve is possibly a sign of shear banding.

The suspension viscoelasticity was also observed to play an important role in the case of

enzymatically pre-treated NFC. Using a viscoelastic Maxwell model, transient effects, which

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resembled those observed in experiments for the enzymatically pre-treated NFC suspension, were

observed. The model demonstrated that such transients are measurable only for suspensions with

small elastic modulus. With higher elastic modulus, such transients are so fast that they will

disappear, in practice, due to the slower settling time of the rheometers. This is also reasonable to

assume, as the NFC flocks formed of longer fibres, in the enzymatically pre-treated case, can be

assumed to have lower elastic modulus compared to the more compact ones formed of shorter

fibres, in the TEMPO-oxidised case.

Considering the model response to a decreasing shear ramp, it can be seen as an implication of what

happens during a papermaking process in the forming stage. When the wet web is formed, there is a

decreasing relative velocity difference between the fluid and the wire, implying a shear gradient

decreasing in time. The picture that emerges from the simulations of such a case is that the flock

formation of the TEMPO-oxidised NFC requires such a long time that, during the forming stage, no

noticeable aggregation can be observed. This is promising for shear bands and other phenomena,

which are completely absent in the dispersed phase, as the relative viscosity differences in this state

are extremely small.

WP8 Demonstrations: Three NFCs were selected to be produced on a large scale and these were

used on a pilot scale for the manufacturing of the selected demonstrators of the WP8

demonstrations. The NFCs used were named as NFC-CTP, NFC-TE/CTP, and NFC-TE/PTS.

Several demonstrators in the three end-use areas were studied, and four different ones as examples

are described here in more detail: two for conventional printed products and two targeting novel

products. In both cases, conventional and more novel coating technologies were used.

Demo 1: Conventional coating on board

Demo 3: Coating for inkjet paper based on curtain coating

Demo 4: Foam coating with functionalised NFC

Demo 5: Conventional coating for barrier packaging

Demo 1: Conventional coating on board

Three NFC grades of the project were then tested in a pilot trial, to see the effect of scaling-up on

the behaviour of these NFCs in the pigment coating colours, as partly replacing latex binder (Demo

1). The coating trial was conducted on the KCL pilot coating machine and in conventional

technology, a bent blade with jet-applicator was used as a coating head.

The results from the KCL pilot plant (coating and printing experiments) imply that most of the

coated board and printing properties with the coatings containing NFC were close to those of the

reference coatings with latex. Because of the big decrease of the coating colour solids, it was

concluded to be very difficult to get benefits from replacing just a part of the latex with NFC.

In the continuation tests in Stora Enso´s pilot plant, the initial target was fine-tuned. Due to limits

of time and available material, it was not possible to do industrial conversion to cartons. However,

some unprinted material was made into small boxes in the lab and showed good convertibility.

These small board packages are shown in Figure 13.

16

Figure 13. Produced shapes and boxes from coated samples.

No major benefits were gained in these trials via NFC in coating colour. There could be some

possibilities to improve the bending stiffness of the board by using NFC in surface sizing. In such a

case, one can expect clearly increased drying demand.

Demo 3: Curtain coating for inkjet paper

In order to be prepared to fulfil the market needs in terms of production output for inkjet photo

papers, paper manufacturers can either invest in new plants or enhance the productivity of existing

machines. The production speed of coated inkjet photo paper is limited by cracking during drying

of the coating layer, and hence limited to rather low production speeds. The cohesion strength

between the nano-pigments and the binder competes with the retraction force of the binder during

drying. The fibre network of the NFC was assumed to counteract the forces and thus reduce

cracking of the coating layer.

Inkjet photo paper was coated on a pilot coater at Schoeller Technocell using curtain coating

technology, which is comparable to the industrial production machines in the company. Two

samples were produced, one reference sample without NFC and another one containing 0.06% NFC

in the coating layer. The cut paper sheets were printed with a Canon PIXMA iP4950 photo printer.

The use of NFC in the coating had a positive impact on paper quality and production efficiency.

The quality was on the same level when printed with pigmented inks or even improved when

printed with a dye-based ink printer. Especially water fastness, absorption, bronzing, and brittleness

are better with NFC, if dye-based inks are used. Besides the beneficial paper quality improvements,

the production speed could be increased by adding NFC to the coating colour. The cracking level

was lower with 0.06 % NFC in the coating colours, which is equivalent to a potential for a coating

speed increase estimated to be 5-10%.

As the final demonstrator for NFC use in inkjet photo paper coating, a photograph of the SUNPAP

project team was printed and handled out during the final conference in Milan (Figure 14).

17

Figure 14. A photograph of the SUNPAP project team was used as one demonstrator. The

photo paper contains 0.06% NFC in the coating layer.

Demo 4: Foam coating with functionalised NFC

Thin layers of cellulose nanofibrils can be applied on the surface by using a novel foam coating

applicator in the KCL pilot coater. The applied amounts are considerably smaller than in

conventional coating. The influences of thin layers on the fine paper surface with unmodified NFC

increased hydrophilicity, and reduced air permeability and small scale roughness (PPS S10),

resulting in glossier and smoother surfaces.

By using NFCs functionalised with inorganic particles, it is possible to create novel activities to

paper surface even with extremely low coat weights, below 1 g/m2. These foam coating trials were

carried out at Zimmer with a new coating head, making even higher coat weights possible. Very

high antibacterial activity of papers could be achieved with thin layers of NFC-TiO2 and/or ZnO

(TiO2 contents were around 0.3% and ZnO contents even lower) under both light and dark

conditions, as already discussed in WP5 NFC functionalisation. NFC-TiO2 also has significant

activity for the oxidation of NO and NOx in low coat weights (Table 3, e.g. in coat weight 0.9 g/m2

and the amount of TiO2 on paper was 0.2%).

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Table 3. NOx photo-degradation in gaseous phase by NFC-TiO2, NFC-ZnO, and NFC-

ZnO&TiO2 foam-coated papers.

Demo 5: Conventional coating for barrier packaging

Barrier coatings were continued on a pilot scale. The base board was coated on CTP's pilot coater.

Coating layers of 10 g/m² containing mainly polyvinyl alcohol with 5 parts of NFC in the matrix

were applied with a SoftTip blade at a speed of 70 m/min, in order to get the gas and grease

resistant layer.

The reels produced were divided into two parts. One reel was sent to Stora Enso in order to perform

the PE extrusion. The second reel was coated once again in the CTP's pilot coater: a 6 g/m² layer of

commercial barrier latex was applied to impart the water resistance. Due to the narrow width of the

reels, LDPE extrusion coating was done at Tampere Technical University. A relatively high

amount of LDPE coating was used, because good hot-sealing properties were targeted. The boards

from the final coating trials were then converted into small packages. These small board packages

(unprinted) are shown in Figure 15.

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Figure 15. End-use barrier packaging demonstrator.

Oxygen barrier measurements were carried out with Oxtran 2/21 (Mocon) apparatus (ASTM D-

3985) at higher (50% RH) moisture content. Higher moisture conditions were considered more

relevant because NFC as a hydrophilic material should absorb moisture and thus give higher

oxygen penetration.

The grease barrier was tested using a modified ASTM F119-82 method. Because some barrier

films tend to fracture in the conversion (creasing and folding), testing was also done for a creased

sample. There was also a target to see if creasing defects would be reduced with the help of PE

coating, and samples were PE coated for this reason. PE coating was done on both sides, in order to

get a more realistic structure for oxygen-tight packages (good enough sealing properties).

There were very large variations in the oxygen barrier results. This was caused by pin-holes in the

coating layer. Pin-holes could be a major problem in higher-speed machines, because faster drying

is needed. The moisture sensitivity of the coating layer will also have an effect. The measurements

were made at 50%. The barrier latex gave a clear improvement when coated on top of the polyvinyl

alcohol and NFC layer. The best results were obtained when the polyvinyl alcohol and NFC layer

was coated with PE. NFC can, in theory, give a good grease barrier. Pin-holes are also a potential

problem here. Adding the barrier latex gave good grease resistance in noncreased samples but not

in creased samples. The PE-coated samples also had good grease barrier properties after creasing.

20

Value chain (Module 1) – Market needs, sustainability, recyclability and

biodegradability evaluations

WP1 Market Needs: The aim of WP1 was to analyse where, when, and how nanocellulose could

be used in selected paper and paperboard end-uses. The tasks in this work package included both

market and technical feasibility assessments of the products developed. In addition, the impact on

European competitiveness was also evaluated. The work in the WP was thus divided into three

different tasks: market assessments, feasibility analyses, and evaluation of the impact on Europeans

competitiveness.

Market assessment was started by mapping and evaluating the market growth potential of paper,

paper-board, and non-woven end-uses. Future consumer needs were researched to distinguish

trends and development drivers. The findings of the analysis were then compared with properties

that nanocellulose was believed to have. As a result, future key end-use properties were extracted

and a nanocellulose opportunity tree for paper and paper-board products could be drawn (Figure

16). The findings of the work showed that there are several potential application areas where

nanocellulose could be used.

Figure 16. NFC opportunity tree for end-uses.

21

The demand for various carton board products is anticipated to grow significantly. Here,

nanocellulose (NFC) could turn out to be beneficial due to its light weight but interesting strength

and barrier properties. All in all, NFC does not only offer possibilities to improve current products

on the market, but it makes it possible to develop completely new types of value-added niche

products fitting into all product groups presented in this study. For example, by functionalising

NFC, a range of new properties like conducting, photoactive, or magnetic papers can be added to

cellulose materials.

Feasibility analyses were conducted to evaluate the most promising process routes and applications

developed during the project. Several different routes were screened during the first phases, but in

the end, three different routes were qualified and finally evaluated. The production concepts in the

respective three routes were different. The results showed that the feasibility of the different routes

is quite different. The main difference was a result that the chemical costs of the chemically pre-

treated NFCs outweighed the higher electricity and capital costs of the enzymatically pre-treated

NFC (Figure 17).

Figure 17. Total costs relative to NFC-CTP.

The target in evaluation of the “impact on European competitiveness” was to analyse the

foreseeable impact that nanocellulose could have on European competitiveness, based on findings

in the SUNPAP project. Moreover, the target was to identify how results presented in the SUNPAP

project could be used and what the links to other European-level research projects were. The results

of the study showed that, for European competitiveness, nanocellulose is one part of the solution. It

combined a possibility for global leadership, a renewable raw material basis, synergy across

sectors, and solutions to challenges facing society, while relying on conventionally globally

competitive European industries, such as the forest industry and the chemical sector. In

nanocellulose, companies can fill certain niches, EU policies populate others, and joint efforts fill in

the final missing components, for the greatest competitive impact to be realised in a never before

seen bio-based ecosystem.

22

WP2 Sustainability assessments: The objectives of work package two (WP2) were to define the

framework and indicators for assessing the sustainability of nanotechnology applications in the

paper industry, guide and support the focus of the project in a sustainable direction, and

demonstrate sustainability aspects (environmental, social, and economic) of the developed

processes and value-added paper products.

During SUNPAP, two different sustainability evaluations were carried out. Initially a first-phase

evaluation was carried out already in the beginning of the project. During this phase, all potential

applications were evaluated by screening. During a second phase, a more detailed approach for

selected applications was carried out, which also represented the final and complete sustainability

assessment. During this evaluation, all three pillars of sustainability were included: economic,

environmental, and social sustainability.

Economic assessment focused on private costs, which is the bottom line in NFC manufacturing and

applications. The socio-economic impacts included evaluation of suppliers in the supply chain.

Moreover, the social assessment included analyses on the working conditions of NFC

manufacturing and application. Finally, the consumer’s point of view was included, relating to

acceptance of nanotechnology. For the environmental assessment, carbon footprint, acidification

and eutrophication potential, and fossil resource depletion were selected as indicators, as the data

sets were comprehensive for these impact categories. The carbon footprint can be considered to be

the most important indicator, because one of the constraints of NFC manufacturing is the high

energy consumption. Additionally, a water balance was calculated for the nano fibrillated cellulose

(NFC) processes as background information for possible future water footprint calculations. In

addition, the impact of NFC on the product’s end of life was speculated. Furthermore, results from

research on recyclability and biodegradability, which was carried out in WP3, were also presented

in this assessment. A four-stage approach was used in the LCA analysis (Figure 18).

Figure 18. The four stages of life-cycle assessment.

23

Nano fibrillated cellulose (NFC) was produced by modifying dissolving sulphite pulp by chemi-

mechanical means from Domsjö pulp mill in Sweden. Three different preparation methods were

used both at CTP and PTS. The environmental impacts were calculated for all of them, based on

expert estimations and theoretical data. The environmental impacts for the applications with NFC

were calculated for SBS board using NFC in the coating to replace partly latex, and for wet-laid

non-woven to reduce the basis weight by a small addition of NFC. For the SBS case, the changes in

environmental impacts were negligible, due to the very small amounts replaced in coating. For the

wet-laid non-woven, the trend was very positive. The use of NFC enabled a lower basis weight and

led to more than a 30% lower environmental impact (Figure 19).

* No decrease in energy need in wet-laid process

Figure 19. Carbon footprint of wet-laid non-woven.

The social and economic effects of the application cases were found to vary. The gross value added

was positive for the wet-laid non-woven case. In the coated board case, the value added was

positive with one NFC production route and negative with the other two. Employment effects were

found to be positive in the coated board case and negative in the non-woven case.

WP3 Recyclability and biodegradability evaluations were carried out partly on small-scale

samples and partly with the larger amounts received from the demonstration trials.

Recyclability of packaging products and de-inkability of graphic papers were carried out. Two

types of paper products from WP6 were tested in terms of recycling/de-inkability on a lab scale:

introduction of NFCs by foam coating for inkjet printing, and partial substitution of latex by MFC

in the coating layer for LWC products. As a general conclusion, for the samples tested, it appears

that the introduction of NFC in paper products did not modify to a large extent the recyclability/de-

inkability compared to the same product made without NFC: de-inking of the inkjet prints was not

improved and LWC samples printed with heatset were fully de-inkable. Besides, the mechanical

properties of the recycled pulp were not modified compared to the reference.

In the case of the introduction of NFC by foam coating for inkjet printing, anionic surfactant was

required for foam coating, which induced some drawbacks during de-inking (an increase in

chemical consumption in wet-end and a higher amount of sludge generated during flotation), even

24

if a slight ink removal improvement was observed (but not sufficient to reach the de-inkable criteria

according to the de-inking score from ERPC). Whatever the nature of the NFC introduced (NFC or

functional NFC), pigmented inkjet prints could not be considered as de-inkable even if modification

of the nature of the NFC could induce some slight improvement in ink removal. On the other hand,

the presence of the TEMPO pre-treated NFC led to a change in surface chemistry of the NFC,

leading to a more hydrophilic character of the NFC (by conversion of hydroxyl group to carboxylic

group). Besides, this surface chemistry change also induced an increase in the potential risk of

paper machine plugging and a slight increase in cationic demand, meaning higher chemical

consumption in the wet-end of the paper machine.

In the case of LWC paper printed with heatset offset technology, the partial substitution of latex by

MFC and the removal of CMC in the coating layer did not change de-inkability and the risk of

deposit on the paper machine wire. The main difference observed corresponded to the nature of

MFC: undried MFC led to faster kinetic of flotation, certainly due to a difference in resistive

strength of the coating layer, but it did not modify the flotation selectivity.

For the final tests, three demonstrators were selected, considering only products that will be

collected and recycled (and if produced in sufficient amounts in the SUNPAP project for

recycling/de-inking testing):

Demo 1 (Conventional coating on board): Recycling on a pilot scale

Demo 2 (Conventional coating on paper LWC): De-inkability on lab and pilot scale in paper

for a recycling mixture encountered in wood-containing de-inking lines producing

newsprint, SC, or LWC papers

Demo 5 (Barrier packaging): Recyclability on a lab scale

During these tests, special attention was paid to the behaviour of the overall recycling/de-inking

line and to the final recycled/de-inked pulp quality (mechanical and optical properties).

As a general conclusion, the presence of NFC in these three demonstrators does not induce large

changes in recycling/de-inking. The presence of NFC pre-treated by TEMPO enabled a reduction of

the resistive strength of the coating layer during re-slushing, leading to smaller mineral filler flakes.

This opened some energy saving during pulping and/or deflaking, higher mineral filler content in

the de-inked pulp (associated with lower amounts of sludge produced by de-inking lines), and

better cleanliness of the pulp (i.e. lower visual contamination). The possible negative impact seen

on a lab scale as the risk of a deposit on the paper machine wire was confirmed in large-scale tests

with NFC pre-treated by TEMPO.

Biodegradability studies: NFCs produced in WP5, particularly chemically grafted NFCs to impart

hydrophobic properties and physically modified NFCs (by polyelectrolytes), were investigated in

regards to their biodegradability in an aqueous medium. Standardised methods from ISO, EN, and

OECD were used. The results showed that the intrinsic biodegradability of cellulose was not

modified for most of the functionalised NFC analysed: the 90% biodegradation limit to claim

biodegradability of materials was easily reached within a feasible timeframe (Figure 20). The NFCs

used for demonstration of SUNPAP corresponded to biodegradable products in an aqueous

medium.

25

Figure 20. Biodegradation kinetics in an aqueous medium of NFC suspensions.

As far as paper samples are concerned, coated paper boards from WP6 were analysed, especially

the products coated with unmodified NFC and functionalised NFC. The ultimate biodegradability

under controlled composting conditions of these samples was demonstrated with a biodegradability

reaching the 90% limit within 60-70 days. Two of the demonstration products from WP8 (Demo 1

and Demo 5) were then analysed to determine if they met the requirements for certification of

compostability: ultimate biodegradability in compost, disintegration of the samples, and ecotoxicity

from compost after disintegration.

The different coated papers including NFC products did not have a negative impact on the good

biodegradability of paper and board in a compost environment. To complete this assessment,

disintegration in compost was tested and the quality of the obtained final compost was analysed, as

well as the absence of any eco-toxicity effect in respect of seed germination and plant growth. The

tested paper board products, including NFC pre-treated by enzyme or TEMPO treatment in the

coating layer, passed the different tests and their compostability was confirmed.

26

Health and Safety (Module 4) - Toxicity and risk assessment

WP9 Toxicity: This work package provided the necessary data for hazard characterisation and

final risk assessment. Originally, the WP involved three tasks: characterisation of aerosols and

liquid dispersion of NFC and FNFC, elucidation of the effects of NFC and FNFC at cellular level,

and systemic effects of NFC and FNFC in vivo. During the course of the project, and because of the

special nature of the NFCs/FNFCs, the material characterisation was practically done in WP4. The

work in WP9 was done according to the hazard analysis outlined in WP10 (Figure 22).

In the beginning, the focus was on the in vitro toxicity and the cellular effects of NFCs. The toxicity

was assessed using i) cytotoxicity assays, which measure the harmful effects of the test materials on

cultured mammalian cells, ii) immunotoxicity assays, which give an indication of the potential of

the test materials to interfere with the basic immunological phenomena, and iii) genotoxicity tests,

which detect harmful effects on the DNA or chromosomes. Commercial MFC (Arbocel®) was used

as a reference material with some of the assays, when the suitability of test procedures was

assessed. The actual test materials used for in vitro studies included NFC samples prepared with

and without enzymatic pre-treatment or with TEMPO oxidation before homogenisation.

None of these materials was harmful to exposed cells, indicating a lack of cytotoxicity. An example

of a typical cytotoxicity test result is given in Figure 21.

Figure 21. Typical results of a cytotoxicity assay performed with one of the project samples.

The test measures the total protein content (TPC) of the exposed cells. TPC in

unexposed cells is 100% and 80% is considered as the toxic breakpoint. This

breakpoint was not reached even at very high NFC concentrations.

In the immunotoxicity assays, there were some marginal indications of inflammatory response in

human peripheral lymphocytes, but only when these cells had been exposed to bacterial

lipopolysaccharide (LPS) before treatment with NFCs. LPS is a potent immunotoxic agent, and the

results indicate that although the NFCs are not likely to induce inflammatory responses by

themselves, they could have synergistic effects with the microbial contamination in NFCs. Also in

27

genotoxicity assays there was an indication of DNA damage caused by the NFCs. The effects were,

however, weak, and no clear dose response could be detected.

The immunotoxic and genotoxic effects together indicated a need for further in vivo studies. The

tests included the effects of a selected TEMPO-oxidated NFC on a nematode worm

(Caenorhabditis elegans) and the so-called pharyngeal aspiration test in a mouse. Despite being a

simple organism C. elegans has a digestive system, nervous system, xenobiotic metabolism, and

developmental cycle, which makes it a suitable test organism to study effects that cannot be

detected in cell cultures. The mouse pharyngeal aspiration test was chosen because the likely

human exposure is via inhalation. In the test, exact doses are applied to the mouse pharynx, and

subsequently the inflammatory and genotoxic responses of the test material can be assessed from

the cells that have been harvested by a bronchialveolar lavage (BAL) from the exposed cells.

While no harmful effects were seen in the C. elegans model, indicating that the NFC does not

penetrate the cuticulum or gastrointestinal barrier to an extent that causes detectable damage, the

BAL-associated cells harvested from the exposed mice indicated an inflammatory response.

However, no signs of genotoxicity were found in these cells.

Taken together, the toxicological results indicate that the tested NFCs do not interfere in the cellular

metabolism in a way that would lead to cytotoxicity. The weak indications on in vitro genotoxicity

were not confirmed in in vivo trials, while both in vitro and in vivo data indicate that an

inflammatory response is possible, and this has been taken into account in the actual risk

assessment (WP10).

WP10 Risk assessment: A risk can be defined as a hazard multiplied by its probability, with

probability being usually correlated with the expected exposure. This WP was devoted to the actual

risk assessment based on the toxicological data available in the literature and accumulated during

the project. The work started with an extensive literature study on the available published

toxicological data and risk assessment methodology related to NFC or NFC-type materials. On the

basis of the limited information available, a hazard assessment scheme outlined in Figure 22 was

devised.

The generated data was used to outline a preliminary risk assessment, mainly based on the in vitro

data. In the preliminary assessment, the main identified difficulty was the lack of reliable data or

even reliable estimates of likely exposures. Because of this, in the final risk analysis, the so-called

control banding (CB) approach was applied. CB is actually a risk management tool that is

applicable when the available data are limited. Two CB scenarios, the so-called CB-Nanotool

(Lawrence Livermore National Laboratory) and Stoffenmanager Nanotool (the Dutch Ministry of

Social Affairs and Employment) were actually used. In both of these scenarios, estimations of

hazard and exposure are given scores, and the combination of the scores is the basis of the risk

estimation. The main difference between the two approaches is that the hazard evaluation CB

Nanotool is based on available toxicological information, while the Stoffenmanager Nanotool

focuses on the physicochemical aspects of the material to be assessed.

28

Figure 22. The general hazard assessment/characterisation scheme applied in the project.

According to the results, both CB approaches gave NFC a very high hazard class. This was,

however, a result based on the very conservative starting point of the CB tools, which gives high

hazard scores to unknown parameters and, in the case of Stoffenmanager Nanotool, the highest

hazard class to insoluble nanoscale fibres. In addition, the toxicological data required by the CB

nanotool (carcinogenicity, reproductive and dermal toxicities) does not exist for NFC, and testing

for them was really beyond the scope of the project.

As a general conclusion, the current CB scenarios clearly overestimate the hazards and are probably

not suitable for NFC-type materials. The toxicological data obtained during the project do not

indicate major concerns, except for the occupational inhalatory exposure, which, however, can be

managed by standard protective measures. The toxicological testing scheme applied in the project

was found to be compatible with the first tier hazard and risk assessment according to the latest ISO

standard made for nanomaterial risk evaluation.

29

3. Potential impact, main dissemination activities, and exploitation results

Potential impact: When interpreting the results of such novel products and their impacts, it is

important to be aware that many assumptions are made and many generic data sets were used.

Therefore the presented results were very strongly case dependent. The results can be seen as trends

and indicate that no environmental hazards are likely to arise as a result of including NFC in the

applications studied.

From an environmental perspective, the main differences between the three different NFC

production options can be found from electricity consumption, raw material efficiency, and water

consumption. Enzymatically pre-treated NFC production is an energy-intensive process, however,

with high yield and low water consumption, while chemically pre-treated NFC consumes less

energy but more water in the process and stays behind in the yield.

NFC can be applied in coatings to reduce the need for latex. This was demonstrated in SBS board

pigment coating. However, the amounts of NFC represented less than 1% of the total product and

the environmental effects were not recognisable. Applying NFC in bulk structures will enable a

reduced need for raw materials as demonstrated in the wet-laid non-woven application. With lower

weight and less raw materials, all the environmental burdens are also significantly lower. When

combining both approaches using NFC in bulk structures and barrier coatings in large volume

packaging paper and board applications, a significantly lower environmental impact can be

expected.

The production of NFC is very energy-intensive and this is a threat when large amounts of NFC are

applied, at least in countries where the grid mix is very fossil fuel-based. Furthermore, the low

concentrations of NFC increase the drying energy demand of the applied NFC due to the use of

water in high volumes. However, the energy consumption does not seem to be higher than in the

production of latex. Another threat is related to the embodied environmental burden of chemicals

used in the production of NFC. The oxidation chemicals can cause high economic impacts when the

cleaning technologies needed to treat the process effluents are taken into account.

Both functionalised NFC and reference natural NFC were assessed for their biodegradability in an

aqueous environment. Functionalised NFC showed a lower biodegradation rate than NFC only, but

the threshold biodegradation limit of 90% was reached within the test duration. In addition, the

results of the biodegradability tests confirmed that the innovative coated board material containing

the natural (non-functionalised) NFC or even slightly functionalised NFC is suitable for recovery in

the organic recovery route.

Economic and social sustainability assessment of the demonstrators showed that there is no NFC

production route and application that would be the best from every aspect measured by the different

indicators. Thus, the observations on both application cases are collected under a SWOT analysis

framework and presented in Figure 23 and Figure 24.

From an economic point of view, the application of NFC in coated board does not seem to bring

cost savings, and has a negative impact on product profitability when compared to the reference

product. NFC replaced binder by 1:1 in the case studied. If the replacement ratio could be

improved, or if NFC could also be used in a bulk structure making leaner products possible, the

30

application would be more feasible. The production of lean products by adding NFC does not

decrease the production amounts because in most cases the production capacity in board production

machines is limited by the drying capacity, and therefore higher speeds can be used. Using NFC in

higher added-value products as barrier-coated products would also make the situation more

profitable.

The replacement of part of the binder by NFC has a positive employment impact when looking at

the total number of people employed directly in the application and indirectly in the suppliers’

business. The impact on value added is positive only in the case of one NFC production route.

Figure 23. Key conclusions of the studied pigment coated board application.

The application of NFC in wet-laid non-woven, for its part, seems to bring cost savings and has a

positive impact on product profitability when compared to the reference product. The cost savings

in raw material costs could also provide opportunities for entering new market areas.

The replacement of part of the binder and fibre by NFC has a positive impact on value added when

looking at the total sum of direct changes in the application and indirect changes in the suppliers’

business. The total impact on employment is, however, negative. As mentioned above, a lower need

for raw material leads to a lower environmental burden.

The common weakness of both the applications is that the occupational risks related to nano-sized

fibres are not yet very well known, but this is something that will improve as the research proceeds.

A risk-related threat from both applications is that, if the safety issues related to nanomaterials are

miscommunicated, it can cause major problems.

31

Figure 24. Key conclusions of the studied non-woven application.

The production of NFC and its application to paper industry products is a rather young field of

research. More investigation is needed, and the sustainability aspect should guide the development.

The indicators studied in this assessment could be also improved by further work on NFC

production and application technologies.

As an overall conclusion, it looks evident that nanocellulose will be added in the future, not only in

special products for niche markets, but also widely in different kinds of packaging paper and board

products with high production volumes. More product development work in the area of using NFC

to increase strength in bulk structures or create novel functionalities with surface treatments is still

needed. The important impact of the SUNPAP project on the scientific community was the

numerous publications and dissemination activities that have increased the knowledge of the

possibilities and challenges in this area. The development of the research facilities carried out in the

project or in parallel projects will improve the possibilities to continue the work in the future.

32

Main dissemination activities: The general framework of the collective dissemination plan can be

divided into three groups: a first one, including the set-up of the project website and all the periodic

activities already planned from the beginning (project website updating, newsletters); a second one,

concerning all the activities developed during the project; and a third one, composed of those

activities that were planned but will be implemented after the end of the project, as dictated by the

IPR rules agreed among partners.

The project website was established and managed by the project coordinator, http://sunpap.vtt.fi.

The open access project website was the major channel for advertising events and communicating

news and public deliverables, including all lectures given in the two SUNPAP open conferences. In

addition, it contains links to project partners’ websites, as well as a link to confidential material for

project partners. The Doha system provided by the project coordinator through the VTT extranet

has been widely used by the project partnership for internal communication, and for exchanging all

the documents developed throughout the project. Common rules for project work were collected in

the project manual for internal communication and the agreed rules for making publications and

managing foreground were summarised in the IPR management procedures, for appropriate

management of the project.

The newsletters (http://sunpap.vtt.fi/publications.htm) were published on the project website every

six months and provided a fast and simple up-to-date means of communication of the most relevant

public results. The first open workshop was organised in Espoo, Finland. The main focus in the

presentations was on the laboratory work carried out in the project. The event had a total of 77

participants, mainly from research organisations and universities from Scandinavia and central

Europe. The second event, the final conference, was held in Milan, Italy. The number of

participants was slightly higher, with 81 participants, with industry covering almost 50% of the

audience, and significantly more participants from southern Europe. The main focus in the

conference was on pilot-scale work and demonstrations. The conference was also attended by non-

European industrial representatives from Japan and Brazil. The programmes and presented

materials can be found at http://sunpap.vtt.fi/events.htm.

Seven scientific peer reviewed publications are already public and two more have been submitted

and accepted to be published soon. Project partners were involved in 40 other dissemination

activities. Altogether, almost 80 oral presentations or posters were disseminated in different

workshops and conferences where both the scientific community and industry had representatives.

Most of the conferences had an international audience.

33

Exploitation results: Project results can be widely used in the paper, board, and packaging

industry.

The use of NFC as an additive in inkjet coating colours showed promising results. The use of NFC

in coating colours in order to increase the speed on production lines can be started as soon as

suitable NFC quality is on the market. The main impact is better competitiveness with lower

environmental impacts.

The use of NFC in wet-end applications and in coating applications to produce lean non-woven

structures has high potential in niche products. The main impact is lean materials with better

competitiveness and lower environmental impacts.

The results of the use of NFC in a board bulk structure on a laboratory scale have shown similar

potential to those in non-woven applications and these can be widely applied in any packaging

board applications. The main impact is lean materials with better competitiveness and lower

environmental impacts.

The results regarding barrier properties, carried out as postgraduate work, showed good potential

for the use of NFC as an additive in barrier coating, and these results can be exploited not only for

board materials but also for any paper barrier packaging materials. The main impact is lean barrier

materials with better competitiveness and lower environmental impacts. Further product

development is needed to fine-tune the multilayer structures for different packaging applications.

Foam-coating formulation and process results show high potential for the production of thin layers

from any nanomaterial, making novel products possible in the future. In this area, more work is

needed on both product development and scaling up the running speed. The main impact is lean

novel products with better competitiveness and added value.

The developed methodology concerning health and safety aspects can be used as background

material for the future targets aiming to homogenise and update the current standards in the toxicity

testing field. The safety results will also be used in databases, thus making them available as a solid

basis for recommendations, and contributing to answering the questions and needs for national

regulation and legislation authorities.

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4. Contact details

The project partners were:

Research organisations:

VTT Technical Research Centre of Finland, Finland

Papiertechnische Stiftung, PTS, Germany

Centre Technique du Papier, CTP, France

Innovhub - Stazione Sperimentale per L’Industria, Italy

Grenoble INP Pagora, France

Finnish Institute of Occupational Health, Finland

Universities:

Universidade de Aveiro, Portugal

Karlstad University, Sweden

TUT Foundation, Finland

Aalto University Foundation, Finland

SME partners:

Cavitron vom Hagen & Funke GmbH, Germany

Hansa Industrie-Mixer GmbH & CO. KG, Germany

BioSafe - Special Laboratory Services Oy, Finland

NanoSight Ltd, U.K.

J. Zimmer Maschinenbau GmbH, Austria

Industrial partners:

Colorobbia SPA, Italy

Schoeller Technocell GmbH & Co KG, Germany

Pöyry Management Consulting Oy, Finland

J. Rettenmaier GmbH, Germany

Stora Enso AB, Sweden

UPM-Kymmene Oyj, Finland

Ahlstrom Research and Services, France

The project was co-ordinated by VTT, Finland.

The co-ordinator was Dr. Ulla Forsström, e-mail ulla.forsstrom@vtt.fi